A failed test of Mercedes' new radar braking system that resulted in a three-car pile-up last week has been exposed as a sham for the benefit of television that went horribly wrong. Mercedes engineers knew the radar technology wouldn't work in the steel warehouse the demo was supposed to take place in but they were bullied into "simulating" the test by AutoBild journalist, Michael Specht, according to reports.

Specht conspired with the Mercedes engineers to brake manually, faking the effects of the system. Since drivers wouldn't be able to see the cars in front of them because of smoke used to mimic driving on a foggy night, a block of wood was used to mark the point where drivers should brake. This plan went awry because the suspension fitted to the Mercedes S-class cars meant the drivers (one of whom was Specht) failed to notice running over the wood, leading to a pile-up.

All this was filmed in front of the rolling cameras of Stern TV, whose staff thought the failure was genuine and reported it as such. But Specht was carrying audio recording equipment which revealed his subterfuge. Specht was fired from MotorBild while a number of Mercedes engineers also face possible disciplinary action, the UK's Channel 4 reports. Motoring websites have more news on the fiasco which leaves open the disturbing question of what would have happened if the faked tests has succeeded, a scenario that might have created false confidence in the safety technology. ®